Fuel flow shaper

ABSTRACT

A system including a flow shaper configured to be positioned in a spout such that fuel flowing through the spout passes through the flow shaper and exits in a fuel stream. The flow shaper includes an outer wall and a plurality of cavities formed therein, each cavity having a L/D ratio. An average L/D ratio of the cavities, weighted by cross sectional area, is at least about 8:1.

This application claims priority to, and is a continuation-in-part of,U.S. application Ser. No. 12/339,940 filed on Dec. 19, 2008, the entirecontents of which are hereby incorporated by reference.

The present invention is directed to a device for aligning fluid flow,and more particularly, a device for aligning the flow of fuel through anozzle.

BACKGROUND

Fuel dispensers are widely utilized to dispense fuels, such as gasoline,diesel or other petroleum products, biofuels, blended fuels or the like,into the fuel tank of a vehicle or into other vessels. Many fuelingnozzles include obstructions in the flow path that induce turbulence,vortices, and other turbulent eddy flows. For example, internal passagesin the nozzle body, the interface between the nozzle body and the spout,and components in the spout such as an attitude device, sensing tube andsensing tube fitting may present obstructions. Even when the nozzle bodylacks significant obstructions, the fuel flow may include turbulence,vortices, and other turbulent eddy flows due to the introduction of thefuel flow into the nozzle body, or due to other upstream conditions.Regulatory recommendations and industry standards limit the length ofthe spout, and therefore the fuel is typically unable to dissipateturbulence and reach a uniform flow pattern prior to exiting the spout.

The turbulent flow of fuel exiting the nozzle can present variousdifficulties. For example, many nozzles utilize an automatic shut-offdevice which includes a sensing port positioned near the end of thespout. A poor spray pattern of fuel exiting the nozzle can cause splashback of the fuel from the walls of the vehicle fill pipe. The splashback can reach the sensing port of the shut-off device, thereby causingnuisance shut offs. Exiting fuel may also wick upwardly along theunderside of the spout, which can also cause nuisance shut offs.

Turbulent flow and/or poor spray patterns of fuel exiting the nozzle canalso affect the performance of the system when refueling vehicles whichinclude an onboard refueling vapor recovery (“ORVR”) system. Inparticular, liquid seal ORVR systems are typically designed such thatthe vehicle fill pipe has a progressively reduced inner diameter. Thisconfiguration is provided so that fuel flowing into the fill pipe cancover or extend continuously across the cross section of the fill pipe,during refueling, to form a liquid seal which prevents fuel vapor fromescaping through the fill pipe. The reduction in diameter of the fillpipe also causes a vacuum to be generated during refueling due to theventuri effect of the entering fuel stream.

Many fuel dispensers are configured to capture vapors emitted from avehicle fuel tank during refueling, and return the vapors to theunderground fuel storage tank. For example, stage II vacuum assist vaporrecovery systems utilize a vapor pump to capture vapor and return thecaptured vapor through a vapor path of the fuel dispenser back to theullage space of the underground fuel storage tank. Stage II vacuumassist vapor recovery systems may be configured to detect anORVR-equipped vehicle, and cease operation of the vapor pump upondetection of an ORVR-equipped vehicle (i.e., if a vacuum is detected atthe point of refueling, or at the end of the nozzle).

However, if fuel flow exiting the nozzle has sufficient turbulenceand/or an undesirable spray pattern, the flow stream may jet toward thenarrowed neck of an ORVR fill pipe in a non-uniform manner. In thiscase, the fuel may fail to extend continuously across the cross sectionof the fill pipe, which can cause the vehicle ORVR system to fail togenerate a sufficient vacuum at the point of refueling. The fueldispenser may thus fail to identify an ORVR-equipped vehicle as such. Inthis case, the vacuum pump of the fuel dispenser may continue tooperate, which causes fresh air to be draw into the ullage space of theunderground fuel storage tank. This fresh air causes excessiveevaporation of the volatile fuels in the storage tank, which can causepollutants to be released into the atmosphere by venting.

SUMMARY

In one embodiment the invention is a nozzle system in which turbulenceof the exiting fuel stream is reduced and improved spray patterns areprovided. In particular, in one embodiment, the invention is a systemincluding a flow shaper configured to be positioned in a spout such thatfuel flowing through the spout passes through the flow shaper and exitsin a fuel stream. The flow shaper includes an outer wall and a pluralityof cavities formed therein, each cavity having a L/D ratio. An averageL/D ratio of the cavities, weighted by cross sectional area, is at leastabout 8:1.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front perspective view of a nozzle;

FIG. 2 is a side cross section of the spout of the nozzle of FIG. 1;

FIG. 3 is a front perspective view of the spout of FIG. 2;

FIG. 4 is a detail view of the area indicated in FIG. 2;

FIG. 5A is a side cross section of the flow shaper of FIGS. 2 and 4;

FIG. 5B is an end view of the flow shaper of FIG. 5A;

FIG. 5C is a front perspective view of the flow shaper of FIG. 5A;

FIG. 5D is a rear perspective view of the flow shaper of FIG. 5A;

FIG. 6A is an end view of the tube insert of FIGS. 2 and 4;

FIG. 6B is a side cross section of the tube insert of FIG. 6A;

FIG. 6C is a front perspective view of the tube insert of FIG. 6A;

FIG. 7 is an end view of another embodiment of the flow shaper;

FIG. 8A is an end view of another embodiment of the flow shaper;

FIG. 8B is a side cross section of the flow shaper of FIG. 8A;

FIG. 8C is a rear perspective view of the flow shaper of FIG. 8A;

FIG. 8D is a front perspective view of the flow shaper of FIG. 8A;

FIG. 9 is an end view of another embodiment of the flow shaper;

FIG. 10 is an end view of another embodiment of the flow shaper;

FIG. 11 is an end view of another embodiment of the flow shaper;

FIG. 12 is an end view of another embodiment of the flow shaper;

FIG. 13 is an end view of another embodiment of the flow shaper;

FIG. 14 is an end view of another embodiment of the flow shaper; and

FIG. 15 illustrates one embodiment of a velocity profile of fluid insidea chamber.

DETAILED DESCRIPTION

FIG. 1 illustrates a nozzle or dispenser body 10 configured to beinserted into the fill pipe of a vehicle fuel tank. Fuel is pumped froman underground fuel storage tank to the nozzle 10, through the spout 12and into the fill pipe of the vehicle fuel tank. The nozzle 10 mayinclude an optional vapor boot or bellows 14 which surrounds at least anupper end of the spout 12 to aid in vapor recovery. The nozzle 10includes a lever 16 coupled to a main vapor valve and a main fuel valve(not shown) such that when the lever 16 is gripped and pivoted upwardly,the main valves are correspondingly opened, thereby allowing the flow offuel and vapor through fuel and vapor paths of the nozzle 10,respectively.

As shown in FIG. 2, fuel which enter the nozzle 10/spout 12 flows past acheck valve 18, along the length of the spout 12 and passes through aflow shaper 20 positioned at or near the distal end of the spout 12. Thespout 12 may have a shut-off opening or sensing port 22 formedtherethrough. In the illustrated embodiment, the sensing port 22 ispositioned on an underside of the spout 12, near the tip 24 of the spout12. The sensing port 22 is in fluid communication with a tube 26 via atube fitting 28, as will be described in greater detail below.

The tube 26 is positioned in the spout 12, and an upstream end of thetube 26 is fluidly coupled to a shut-off device or circuit (not shown)which compares the pressure in the sensing port 22 to the dynamicpressure generated by a venturi effect of flowing fuel in the nozzle 10.When the differential pressure becomes sufficiently great, the shut-offcircuit causes a shut-off mechanism to release the lever 16 and closethe main fuel and main vapor valves, thereby interrupting the fuelingprocess. For example, when the sensing port 22 is blocked or closed(i.e., temporarily, due to foam or splash back of liquid fuel) thevacuum levels in the shut-off circuit significantly increase, therebytriggering the automatic shut-off mechanism.

Accordingly, as noted above, splash back of fuel during the refuelingprocess can land on the sensing port 22, thereby triggering shut offbefore the vehicle fuel tank is full. These nuisance or premature shutoffs require the customer/operator to re-engage the nozzle 10 and lever16, thereby adding wear and tear on the refueling components, andcausing aggravation to the customer/operator.

The flow shapers 20 disclosed herein can help to align and straightenthe flow, remove turbulence, and ensure a relatively straight andconsistent flow of fuel exiting the spout 12. As best shown in FIGS.5A-5D, in a first embodiment the flow shaper 20 includes an outer wall30 and an inner wall 32 which is entirely radially spaced away from theouter wall 30, and generally concentrically positioned with respect tothe outer wall 30. In the illustrated embodiment, both the outer 30 andinner walls 32 are generally cylindrical. However, the outer wall 30 maytake on various shapes as desired to conform to the inner surface of thespout 12, and the inner wall 32 can also take various shapes as desired.

The flow shaper 20 includes a plurality of generally flat vanes 34extending generally radially between the outer 30 and inner 32 walls. Inthis manner, the flow shaper 20, and in particular, the inner wall 32,defines an inner cavity, chamber or channel 36. The outer wall 30, innerwall 32 and vanes 34 define a plurality of outer cavities, chambers orchannels 38 that generally surround and/or extend generally radiallyaround the inner cavity 36. In particular, the outer cavities 38 maysurround and/or extend radially around at least a majority of theperimeter of the inner cavity 36 (i.e. at least about 270 degrees in theillustrated embodiment). Each cavity 36, 38 may have a generally uniformshape/cross section, and lack any significant obstructions therein.

During fuel dispensing, fluid flowing down the spout 12 enters thecentral cavity 36 and each outer cavity 38. The upstream surface of thewalls 30, 32 and vanes 34 physically redirect the fuel flow into thecavities 36, 38, thereby dividing the flow into a plurality of discretestreams.

As will be described in greater detail below, various arrangements ofwall, vanes, etc. may be provided to form cavities, chambers, orchannels which divide the fluid flow, and receive the fluid flowtherethrough. Each of the cavities may have a L/D ratio, whichrepresents a ratio of the length of the cavity to its hydraulic oreffective diameter. The hydraulic diameter of each cavity represents thediameter of a tubular/cylindrical component with a circular crosssection which provides the equivalent surface area/drag as thatparticular non-cylindrical cavity.

The L/D ratio for each of the cavities may be selected to ensure thatfuel flow exiting from that cavity is fully developed, or nearly fullydeveloped. Although the L/D ratio can vary depending upon the type offluid, flow conditions and the like, classical fluid dynamic equationsand experimentation has shown in normal operating conditions (i.e., inone case, for gasoline with a temperature range of 0° F. to 120° F.),for incompressible fluids and liquid fuels, a L/D ratio of at leastabout 10:1, is sufficient to provide fully developed flow for aparticular cavity. This ratio does not depend upon the velocity of thefuel flow, but assumes that fluid flow fills the cross sectional area ofeach cavity (i.e. throughout the flow domain) to be able to become fullydeveloped.

The L/D ratio required to provide fully developed flow may depend uponthe viscosity of the fluid, which can vary for different types of fuel,varying temperatures, etc. For example, for use with ethanol, a L/Dratio of at least about 5:1 may suffice. However, at least a 10:1 ratio,or at least a 8:1 ratio, or at least a 5:1 ratio has been found to besufficient for a wide variety of fuels under various conditions.

As flow first enters a cavity, frictional forces from the walls of thecavity are applied only to outermost portions of that fluid stream,adjacent to the walls. For a 10:1 L/D ratio scenario, by the time fluidhas traveled ten times the hydraulic or effective diameter of thecavity, the frictional forces imparted by the walls of the cavity aregenerally sufficient to reach the center, or all, of the fluid in thatcavity. In this case, the walls have exerted frictional forces upon allfluid exiting that cavity and provide a fully developed flow, or nearlyfully developed flow, thereby increasing stability and reducingturbulence of the flow. Thus, the surface area of the walls of thecavities produce sufficient pressure drop, as the fluid passestherethrough, to cause tumbling and rotary vortices elements of the flowto become reduced or eliminated. In other words, fully developed flowmay have a generally uniform (i.e., stable) velocity profile such thatthe velocity profile for fluid exiting the cavity is the same as avelocity profile for fluid just upstream of the exit location.

FIG. 15 illustrates the principles described above by showing the growthof a boundary layer 39 and various velocities profiles 41, 43, 45 alongthe length of a cavity. It should be understood that FIG. 15 is notnecessarily to scale and that the boundary layer 39 and velocityprofiles 41, 43, 45 may have differing appearances, and change indiffering manners, than that shown in FIG. 15. Fluid first entering acavity may have a velocity profile as shown at position 41. As fluidmoves downstream through the cavity, the boundary layer 39 growsradially inwardly. At position 43, the boundary layer 39 has grown andfurther influenced the velocity profile compared to position 41.Finally, at position 45, the boundary layer 39 has influenced all of thefluid in the cavity, and the velocity profile 45 is fully developed. Thefully developed velocity profile 45 has a parabolic shape with thegreatest velocity at the center of the cavity, smoothly reducing down toa velocity of zero at the outer edges of the cavity.

The cavities of the flow shaper 20 may be configured such that anaverage of the L/D ratio of the cavities meets a minimum value. Thisaverage may be a weighted average based upon the cross sectional area ofthe cavities. For example, in one case the weighted average L/D ratiofor all of the cavities of the fluid flow shaper 20 may be at leastabout 10:1. In another embodiment, the weighted average of each of thecavities is at least about 8:1. It has been found that providingcavities having a weighed average L/D ratio of at least about 8:1 mayprovide fully developed flow, or nearly fully developed flow, that issufficient to cause tumbling and rotary vortices elements of the flow tobecome reduced or sufficiently eliminated, thereby reducing oreliminating splash-back and reducing premature shut-offs during therefueling process.

Instead of, or in addition to, providing fluid flow that is fullydeveloped, various cavities may instead provide flow that is nearlyfully developed. In this case the velocity profile 47, as shown in FIG.15, is generally shaped as a parabola, and matches the velocity profile45 for fully developed flow by at least about 80% (i.e. no values fromthe curve 47 deviate from the curve 45 by more than about 20%). In otherwords, for nearly fully developed flow, it can be considered that thedifference x between the curves 45, 47 is not more than 20% of theassociated velocity value of the fully developed profile 45. Nearlyfully developed flow can also be considered as a flow condition in whichfluid exiting a cavity has a velocity that is within 10% of the velocityof fluid 1 mm upstream of the exit location. In this case the change influid velocity is relatively low and the fluid flow can be consideredrelatively stable.

Returning to the specific example of the fluid flow shaper 20 shown inFIGS. 5A-5D, it can be seen that fluid exiting each cavity 36, 38,and/or each outer cavity 38 may be fully developed or nearly fullydeveloped flow. However, due to the increased effective diameter of thecentral cavity 36, in one embodiment fluid exiting the central cavity 36may be less fully developed (and may have a lower velocity than thesurrounding fluid). For example, in one embodiment the L/D ratio forouter cavities is about 10:1, and the L/D ratio for the central cavity36 may be less than about 10:1, such as about 5:1. However, because thefluid exiting the outer cavities 38 generally surrounds and“encapsulates” the majority of the fluid exiting the central cavity 36(i.e. at least about 270 degrees in the illustrated embodiment), astable outer ring of fluid generally entraps the less developed coaxialinner core of fluid and significantly prevents any diverging fluidstreams.

As the flow exits the spout 12, the individual streams from the cavities36, 38 will eventually merge and become a coherent single stream,ultimately with a uniform velocity profile. Thus, the outer ring offully-developed or nearly fully developed fluid ensures that the exitingstream, as a whole, has a stable, circular spray pattern with a very lowangle of divergence and little turbulence.

The flow shaper 20 may be positioned close to the end 24 of the spout 12(i.e. within at least about the distance of the diameter, or effectivediameter, of the spout 12 from the end 24) so that the flow shaper 20can influence the exiting flow in the desired manner. However, the fuelshaper 20 can be positioned at any position along the length of thespout 12. In particular, if the spout 12 includes a generally continuousinner surface and lacks significant obstructions, the fuel shaper 20 canbe located significantly upstream of the distal end, and even at oradjacent to the inlet end of the spout 12.

The embodiment shown in FIGS. 5A-5D includes six outer cavities 38.However, the number of cavities 38 can be reduced, in which case it maybe desired to increase if the length of the cavities 38/flow shaper 20.Correspondingly, the length of the cavities 38/flow shaper 20 can bereduced, in which case it may be desired to increase the number ofcavities 38. Thus it can be seen that the number of outer cavities 38does not govern performance, but instead the exposure of the flow to thedrag forces of the walls of the cavities 38, which dissipates theturbulent energy, determines the performance of the flow shaper. Theadded pressure drop as fluid travels through the cavities 38 providesthe energy needed to produce fully developed fluid flow, or nearly fullydeveloped fluid flow. In one embodiment, the flow shaper 20 includes atleast four cavities.

The shaper 20 of FIGS. 5A-5D may be configured such that all streamsexiting the shaper 20 are fully developed or nearly fully developed. Forexample, the length of the shaper 20 may be increased, and/or the sizeof the central cavity 36 reduced, such that fluid exiting all cavities36, 38 is fully developed or nearly fully developed. However, if onlythe outer part of the flow is fully or nearly fully developed, this mayhelp to reduce pressure drop across the spout 12. In particular, if allof the fluid exiting the spout 12 were to be fully developed, this mightin some cases generate a significant pressure drop across the spout 12.This pressure drop could render the spout 12 more prone to resistingautomatic shut offs, since the fluid flow through the upstream venturipath will be slower, thereby generating a lower vacuum pressure. In thiscase, the measured vacuum pressure differential by the shut off circuitwould be lowered, and the shut off mechanism would not have enoughvacuum to disengage the lever 16.

In contrast, if the flow shaper 20 does not fully develop all of thefluid, but only the more critical outer streams, the pressure dropacross the flow shaper 20 is reduced, thereby ensuring proper operationof the nozzle 10 and ensuring proper operation of automatic shut offs.The same advantages apply when all of the fluid is nearly fullydeveloped, instead of fully developed. In addition, if the cavitiesinclude a L/D ratio that is too large, the fluid flow may create toolarge of a back pressure. Accordingly, in some cases the L/D ratio ofany given cavity, or an average of the cavities, or a weighted averageof the cavities, may be no larger than at least about 10:1, or no largerabout 15:1 in another embodiment, or no larger than about 20:1 in yetanother embodiment.

As best shown in FIGS. 5A and 5C, the upstream end 34 a of each vane 34may be tapered such that fluid flowing down the spout 12 first engagesthe radially outer ends of the vanes 34 and gradually engages the innerradial edges of the vanes 34. This arrangement helps to reduce pressurein the fluid and pooling of fuel along the leading edges 34 a of thevanes 34, thereby reducing eddies and other instabilities in the flow.

With a stable stream exiting the nozzle 10, splash back of fuel onto theshut-off port 22 is reduced, thereby reducing premature and nuisanceshut offs. The stable flow pattern provided by the flow shaper 20 (andother embodiments disclosed herein) also ensures that the cross sectionof an ORVR fill pipe of a vehicle being refueled is continuously coveredto ensure proper operation of the ORVR system of the vehicle, whichensures, in turn, that the stage II recovery system of a refuelingsystem (i.e., the vapor pump) is not operated improperly.

The flow shaper 20 can be made of a wide variety of materials, suchnearly any fuel resistent material including, but not limited to,polymers such as acetal, DELRIN® resinous plastic material sold by E. I.du Pont de Nemours and Company of Wilmington, Del., metals such asaluminum, zinc, etc. The vanes 34 and/or walls 30, 32 may be relativelythin to reduce pressure drop and may be, for example, 0.020″ thick orsmaller. As best shown in FIGS. 4 and 5A, the downstream end 34 b ofeach vane 34 may be spaced inwardly from the downstream end 40 of theshaper 20, and the downstream end 24 of the spout 12, so that the vanes34 are recessed and protected from breakage during use of the nozzle 10.

As best shown in FIGS. 5B and 5D, in one embodiment, the flow shaper 20(and other embodiments disclosed herein) does not include outer cavities38 extending around the entire perimeter (i.e., extending 360°) aroundthe inner cavity 36. Instead, in the illustrated embodiment, the flowshaper 20 has an axially-extending cavity 42 along its bottom edge, anda wedge or spacer 44 positioned between two (or more) adjacent outercavities 38 (or positioned in a single cavity) at one end (thedownstream end) thereof, adjacent to the cavity 42. In the illustratedembodiment (as best shown in FIGS. 5B and 5D), the spacer 44 is shapedas a generally triangular component (with a central opening 50) andextends about 90° around the outer perimeter of the shaper 20.

The spacer 44 helps to reduce the formation of a thin meniscus film onthe underside of the spout 12. In particular, fluid from the adjacentouter cavities 38′ may be prone to “creep” downwardly toward each otheralong the outer perimeter of the shaper 20, as shown by arrows 46 ofFIG. 5D. Should these “trickle” fuel streams occur in sufficient volume,in particular in a sufficient volume to reach each other (i.e., meet atthe bottom of the shaper 20), the merged trickle fuel streams 46 maycurl around the lip of the shaper 20 and rise, by capillary action orotherwise, upwardly toward the sensing port 22, as shown by arrow 48 ofFIG. 5D and FIG. 4.

In addition, the trickle streams 46 can merge to form a small pool orpuddle at the bottom of the spout 12/shaper 20. The puddle may grow byentrapping adjacent flowing fuel due to induced drag from the puddlingliquid. In addition, to the extent that there is an existing pool/puddleof liquid fuel, the fluid flowing through the channels 38′ adjacent tothe spacer 44 seeks to drag adjacent, pooling liquid along with it outthe end of the spout 12. If fluid were to creep upwardly sufficiently,the meniscus film of fluid could reach the sensing port 22, therebytriggering an undesired automatic shut off of the nozzle 20.

However, the spacer 44 is designed to prevent such a deformation of asufficient meniscus film. In particular, because the radially outerpoints of the spacer 44 are spaced apart (i.e., by about 90° in theillustrated embodiment), the spacer 44 provides significant distancebetween the adjacent outer cavities 38′. Thus, the spacing provided bythe spacer 44 ensures that the trickle streams 46 of the cavities 38′ donot merge, or if they do, are of very low volume. By sufficientlyspacing the outer cavities 38′, any induced drag from the adjacent fluidstreams upon fluid at the bottom center of the spacer 44 is reduced.Moreover, because the fluid flowing adjacent to the spacer 44 passesthrough channels (i.e. channels 38′) having a relatively high L/D ratio,velocity of the fuel through those channels 38′ is increased, whichcauses fluid to jet out rapidly and decreases the chances of pooling.

Thus, the spacer 20 may be configured to space apart the adjacent outercavities 38′, or their radially outer edges, by at least about 90°, orat least about 60° or a distance of at least about π/D4, or at leastabout π/D6 of the effective diameter of the flow shaper 20. The spacer44 is, in one embodiment, radially aligned with the sensing port 22 toreduce or minimize the generation of a film that can creep axiallyupwardly toward the sensing port 22. The spacer 44 can be any of a widevariety of shapes or forms, other than triangular, so long as the spacer44 provides sufficient spacing between the outer cavities 38′, and inparticular, the radially outward ends of the cavities 38′. In thismanner, the fuel may not be able to wick or curl around the edge of thespout 12 in sufficient volumes/velocity to reach the sensing port 22,and pooling and puddling of fuel at the bottom center of the spout 12 isminimized.

As shown in FIGS. 6A-6C, the tube fitting 28 includes an opening 52formed therein having a minor portion 52 a which extends perpendicularto the spout axis and a major portion 52 b which extends generallyparallel to the spout axis. The tube fitting 28 is received in thecavity 42 of the flow shaper 20, as shown in FIG. 4. As can be seen inFIGS. 5A-5D, the spacer 44 may include an opening 50, and the end 54 ofthe tube fitting 28 is received in the opening 50 of the spacer 44. Thetube fitting 28, in the illustrated embodiment, has a groove 56 adjacentto the end 54 which is designed to receive a clip 58 of the flow shaper20 therein to couple the tube fitting 28 to the flow shaper 20 (see FIG.4).

In this manner, the distal end 54 of the tube fitting 28 fits into theopening 50 of the spacer 44, and helps to provide a generallyfluid-tight spacer 44 through which fluid does not pass. However, thespacer 44 may not necessarily include the opening 50, and the tubefitting 28 may be coupled to the flow shaper 20 in any of a variety ofmanners. In addition, the flow shaper 20 can be retained in the spout 12by any of a variety of means, such as by deforming the tip of the spout12 radially inwardly or by the use of adhesives, staking, set screws,retaining rings, press fits, retaining collars, and the like.

After the tube fitting 28 is mounted to the flow shaper 20, and the flowshaper 20 is mounted in the spout 12, the minor portion 52 b of theopening 52 is in direct fluid communication with, or forms part of, thesensing port 22 (see FIG. 4) and the major portion 52 a of the opening52 b is in direct fluid communication with the tube 26 (see FIG. 2). Inthis manner, the tube fitting 28 allows the pressure from the sensingport 22 to be communicated, via the tube 26, to the shut off circuit.

It should be noted that some previous arrangements for coupling the tube26 to the sensing port 22 may provide an obstruction to flow whichgenerates significant turbulence in the stream of fuel. However, in theflow shaper 20 (and other embodiments) disclosed herein, not only doesthe spacer 44 provide the function of reducing meniscus films which cancover the sensing port 22, but the spacer 44 also makes use of, and isaligned with, the tube fitting 28 so that the tube fitting 28 does notcontribute additional turbulence. In other words, the flow shaper 20incorporates what is otherwise a mere obstruction (the tube fitting 28)in the fuel path, into a functional arrangement.

FIG. 7 illustrates another embodiment 20 a of the fuel shaper. In thiscase, the fuel shaper 20 a has an outer wall 30, and a plurality ofvanes 62 that divide the fuel shaper 20 a into a plurality of cavities64. In the illustrated embodiment, the outer wall 30 is generallycylindrical (although the outer wall 30 can be shaped as desired toconform to the inner surface of the spout 12), and the vanes 62 aregenerally radially positioned and meet at the axial center of the fuelshaper 20 a.

In this case, the flow shaper 20 a has a plurality of cavities 64, eachof which radially extends across generally the entire effective crosssection thereof of the flow shaper 20 a (i.e. from the outer wall 30 toan inner section 68 which does not allow fluid flow therethrough). Inthis embodiment, each of the cavities 64 may have a sufficient L/D ratio(i.e. at least about 10:1 in one case, or at least about 8:1 or 7:1 inanother case) such that the flow exiting each cavity 64 is fullydeveloped or nearly fully developed. Thus, any of a variety of shapesand configurations for the flow shaper, vanes, and cavities may be used,and it may be desired that at least the majority of the outer perimeterof an exiting fluid stream, or at least a majority of the volume of theexiting fluid stream, be fully developed or nearly fully developed.

Another embodiment of the fuel flow shaper 20 b is shown in FIGS. 8A-D.In this embodiment the fuel flow shaper 20 b includes a series of innerwalls 70, 72 defining a set of cavities 74. The inner walls include aset of three major arcs 70, wherein each major arc 70 extends from onepoint of the outer wall 30 to another point on the outer wall 30. In theillustrated embodiment, the ends of a major arc 70 are spaced apart byabout 80° about the circumference of the outer wall 30. Each major arc70 in the illustrated embodiment is a circular arc having a diameterabout equal to the diameter of the outer wall 30. However, the diameter,shape, size and positioning of each major arc 70 may vary as desired.

The fuel flow shaper of FIGS. 8A-D also includes two minor arcs 72, witheach minor arc 72 extending between two of the major arcs 70. Inparticular in the illustrated embodiment each minor arc 72 extendsbetween the center or midsection of two adjacent major arcs 70, and theinner ends of the minor arcs 72 are positioned adjacent to each other atthe center or midsection of the other major arc 70 opposite the spacer44. Each minor arc 72 is entirely spaced apart from the outer wall 30.In the illustrated embodiment each minor arc 72 is a circular arc havinga diameter about equal to the diameter of the outer wall 30, althoughthe diameter, shape, size and positioning of the minor arcs 72 may varyas desired.

The arrangement shown in FIGS. 8A-8D (as well as the various otherembodiments disclosed herein) provides a plurality of cavities 74,wherein cavity 74 has a L/D ratio to provide fully developed flow, ornearly fully developed flow, to fuel flowing therethrough. Moreparticularly, all of the volume of the fluid exiting the fuel flowshaper 20 b may be fully developed, or nearly fully developed, toprovide a stable flow of fluid. This, in turn, reduces or eliminatestumbling and rotary vortices elements in a manner sufficient to providea stable fluid flow and sufficiently eliminate splash back.

In addition, in the embodiment of FIGS. 8A-8D (as well as the variousother embodiment disclosed herein) the plurality of cavities 74 may havea weighed average L/D ratio of at least about 8:1, which has beenexperimentally confirmed to reduce or eliminate tumbling and rotaryvortices elements in a manner sufficient to provide a stable fluid flowand sufficiently eliminate splash back. A weighed average L/D ratio ofat least about 5:1 may, in certain cases, be sufficient to reduce oreliminate tumbling and rotary vortices elements in a manner sufficientto provide a stable fluid flow and sufficiently eliminate splash back.Each cavity 74 of the fuel flow shaper 20 b may have a surfacearea/cross sectional area that is within about 50% of any other cavity74. By having cavities 20 b of roughly the same size, it can be ensuredthat fuel flowing through the fuel flow shaper 20 b is all fullydeveloped, or nearly fully developed, and avoids flow having differinginternal properties which can be difficult to control.

In the embodiment shown in FIGS. 8A-8D (as well as the other embodimentdisclosed herein), the upstream end of each arc 70, 72 may be taperedsuch that fluid flow down the spout 12 first engages the radially outerends of the arcs, as described above in the embodiment shown in FIGS.5A-5D. In addition, in this and other embodiments, the downstream end ofeach arc 70, 72 may be spaced inwardly from the downstream end 40 of theshaper 20, as described above in the embodiment shown in FIGS. 5A-5D, toprovide protection to the downstream ends of the inner walls 70, 72.

The fuel flow shaper 20 c shown in FIG. 9 is somewhat similar to theembodiment of FIGS. 8A-8D, but also includes an intermediate arc 80extending between the center positions of two opposite major arcs 70.The intermediate arc 80 divides the core channel of the embodiment ofFIGS. 8A-8D into two separate “core” channels 74′. The remaining majorarcs 70, minor arcs 72 and channels/cavities 74 are slightly adjusted toaccommodate the intermediate arc 80 to ensure the channels/cavities 74,74′ have roughly the same cross sectional area.

The fuel flow shaper 20 d shown in FIG. 10 is somewhat similar to theembodiment of FIG. 9. However, in the embodiment of FIG. 10 theintermediate arc 80 is not present. Instead, the fuel flow shaper 20 dincludes an outer arc 82 positioned proximate to, and curving about, thespacer 44 to define a cavity therebetween. The outer arc 82 has acurvature in the opposite direction to the curvature of the intermediatearc 80 of the embodiment 20 c of FIG. 9.

The fuel flow shaper 20 e shown in FIG. 11 is somewhat similar to theembodiment of FIG. 10. However, in the embodiment of FIG. 11 the cavitydefined by each major arc 70 is subdivided by a generallyradially-extending stub wall 84 positioned therein. In addition, thecore channel of the embodiment of FIG. 11 is divided by a transversewall 86 extending between the minor arcs 72, and a stub wall 88extending between the transverse wall 86 and the outer arc 82. Oneadvantage of the embodiment shown in FIG. 11 is that the fuel flowshaper 20 e provides relatively small cavities 74, thereby providing arelatively high L/D ratio and improving the stability of flow exitingthe stream shaper. One drawback with this design, however, is that therelatively small size of the cavities 74 increases the pressure drop offluid flowing through the stream shaper. These principles holdsgenerally true as additional walls are added from the fuel flow shaper20 c of FIGS. 8A-D, to the fuel flow shaper 20 e shown in FIG. 11.

The fuel flow shaper 20 f of FIG. 12 provides a bit of a differentapproach than some of the other embodiments described herein. Inparticular, the fuel flow shaper 20 f of FIG. 12 has a plurality ofgenerally circular inner walls 90 defining a plurality of generallycircular cavities 92 positioned about a core chamber 94. A set of endchambers 96 are positioned adjacent to the series of circular cavities92, and a plurality of remainder cavities 98 are positioned between thegenerally circular cavities 92 and the outer wall 30.

The fuel flow shaper 20 g shown in of FIG. 13 is a bit of a hybridbetween the fuel flow shaper 20 f of FIG. 12 and those of FIGS. 8-11. Inparticular, the fluid flow shaper 20 f of FIG. 13 has a plurality ofgenerally circular cavities 100 combined with a plurality of generallyradially extending vanes/walls 102 extending outwardly from a corechamber 104. The radially extending walls 102 and generally circularcavities 100 are positioned about the core channel 104.

The fuel flow shaper 20 h of FIG. 14 includes a plurality of ribs 106that generally follow the curvature of the lower side (in theorientation shown in FIG. 14) of the outer wall 30, and generally extendfrom one side of the outer wall 30 to another side (curving about thespacer 44). Each of the ribs 106 are coupled to, and extend generallyoutwardly from, a generally vertically extending/radially extendingspine 108. The ribs 106 and spine 108 thereby define a plurality ofcavities positioned therebetween.

Each of the various embodiments described and shown herein may followone or more of the basic principles set forth herein, although suchproperties are not required. In particular, the cavities may be sized toprovide fully developed flow, or nearly fully developed flow. Thecavities may be sized to provide a weighted L/D ratio of at least about8:1. Each cavity may have a L/D ratio of at least about 5:1 and lessthan about 20:1, or other values as desired. Each cavity may have asurface area that is within about 50% of any other cavity. The cavitiesmay provide fully developed flow, or nearly fully developed flow, aboutan outer perimeter, or about a majority of the outer perimeter, of thefluid flow. The cavities may provide a fuel flow wherein at least amajority of the fuel flow, by volume, is fully developed flow, or nearlyfully developed flow. Certain ones or more of these features and otherfeatures may help to reduce turbulence and provide a stable, confinedfluid stream.

Having described the invention in detail and by reference to the variousembodiments, it should be understood that modifications and variationsthereof are possible without departing from the scope of the invention.

1. A system comprising: a flow shaper configured to be positioned in aspout such that fuel flowing through said spout passes through said flowshaper and exits in a fuel stream, wherein said flow shaper includes anouter wall and a plurality of cavities formed therein, each cavityhaving a L/D ratio, wherein an average L/D ratio of said cavities,weighted by cross sectional area, is at least about 8:1.
 2. The systemof claim 1 further comprising a spout configured to dispense fueltherethrough, wherein said flow shaper is positioned in said spout. 3.The system of claim 2 wherein said flow shaper is positioned at a distalend of said spout.
 4. The system of claim 2 wherein said flow shaper isconfigured such that each cavity receives part of said fuel streamtherein and such that the entirety of said fuel stream collectivelypasses through said plurality of cavities.
 5. The system of claim 2wherein said flow shaper includes a spacer which blocks the flow of fueltherethrough, wherein said spacer has an outer portion positionedadjacent to said spout and extending at least about 60 degrees about anouter perimeter of said flow shaper.
 6. The system of claim 5 whereinsaid spout includes a shut-off opening formed therein, and wherein saidspacer is generally radially aligned with said shut-off opening.
 7. Thesystem of claim 2 further comprising a fuel reservoir and a hose fluidlycoupled to said nozzle and said fuel reservoir, and a pump configured topump fuel from said fuel reservoir, through said hose, to said nozzleand through said fuel shaper.
 8. The system of claim 1 wherein anaverage L/D ratio of said cavities, weighted by cross sectional area, isless than about 20:1.
 9. The system of claim 1 wherein said L/D ratio ofeach cavity is at least about 5:1.
 10. The system of claim 1 wherein theL/D ratio for any given cavity is the ratio of the length of the givencavity to the hydraulic diameter of the given cavity.
 11. The system ofclaim 1 wherein said flow shaper includes an outer wall and a pluralityof vanes defining said plurality of cavities, wherein said plurality ofvanes includes three major arcs, each major arc extending from oneposition on said outer wall to another, spaced apart position on saidouter wall.
 12. The system of claim 11 wherein each major arc is acircular arc, and wherein the plurality of vanes includes a pair ofminor arcs, each minor arc extending between two associated major arcs.13. The system of claim 12 wherein each minor arc extends betweenmidsections of the associated major arcs.
 14. The system of claim 1further comprising a plurality of vanes defining said plurality ofcavities, wherein an upstream end of each vane is tapered with respectto a direction of fluid flow through said spout.
 15. The system of claim1 wherein each cavity has a cross sectional area that is within at leastabout 50% of the cross sectional area of any other cavity.
 16. Thesystem of claim 1 wherein said flow shaper is configured such that atleast a majority of the volume of said exiting fuel stream is fullydeveloped or nearly fully developed fluid flow.
 17. The system of claim1 wherein said flow shaper is configured such that all of the volume ofsaid exiting fuel stream is fully developed or nearly fully developedfluid flow.
 18. The system of claim 1 wherein said flow shaper isconfigured such that all of the volume of said exiting fuel stream has avelocity profile that does not deviate from the velocity profile forfully developed flow of the fuel stream by more than about 20%.
 19. Thesystem of claim 1 further comprising liquid fuel flowing through saidflow shaper and exiting from said flow shaper, wherein said exiting fuelstream is fully developed on nearly full developed flow.
 20. The systemof claim 1 wherein said flow shaper includes at least four cavities. 21.A system comprising: a flow shaper configured to be positioned in aspout such that fuel flowing through said spout passes through said flowshaper and exits in a fuel stream, said flow shaper being configuredsuch that at least a majority of the volume of said exiting fuel streamis fully developed or nearly fully developed fluid flow.
 22. The systemof claim 21 further comprising a spout configured to dispense fueltherethrough, wherein said flow shaper is positioned in said spout. 23.The system of claim 21 wherein said flow shaper includes a plurality ofcavities positioned such that each cavity receives part of said fuelstream therein and such that the entirety of said fuel streamcollectively passes through said plurality of cavities, each cavityhaving a L/D ratio, wherein an average L/D ratio of said cavities,weighted by cross sectional area, is at least about 8:1.
 24. The systemof claim 22 wherein an average L/D ratio of said cavities, weighted bycross sectional area, is less than about 20:1.
 25. The system of claim21 wherein said flow shaper includes a plurality of cavities configuredsuch that each cavity receives part of said fuel stream therein and suchthat the entirety of said fuel stream collectively passes through saidplurality of cavities, each cavity having a L/D ratio, wherein said L/Dratio of each cavity is at least about 5:1.
 26. The system of claim 21wherein said flow shaper includes a plurality of cavities configuredsuch that each cavity receives part of said fuel stream therein and suchthat the entirety of said fuel stream collectively passes through saidplurality of cavities, wherein each cavity has a cross sectional areathat is within at least about 50% of the cross sectional area of anyother cavity.
 27. The system of claim 21 wherein said flow shaperincludes an outer wall and a plurality of vanes defining said pluralityof cavities, wherein said plurality of vanes includes three major arcs,each major arc extending from one position on said outer wall toanother, spaced apart position on said outer wall.
 28. The system ofclaim 21 wherein said flow shaper is configured such that all of thevolume of said exiting fuel stream is fully developed or nearly fullydeveloped fluid flow.
 29. The system of claim 21 further comprisingliquid fuel flowing through said flow shaper and exiting from said flowshaper in a fuel stream, wherein at least a majority of the volume ofsaid exiting fuel stream is fully developed or nearly fully developedfluid flow.
 30. The system of claim 21 wherein said flow shaper isconfigured such that all of the volume of said exiting fuel stream has avelocity profile that does not deviate from the velocity profile forfully developed flow of the fuel stream by more than about 20%.
 31. Thesystem of claim 21 wherein said flow shaper includes a spacer whichblocks the flow of fuel therethrough, wherein said spacer has an outerportion positioned adjacent to said spout and extending at least about60 degrees about an outer perimeter of said flow shaper.
 32. The systemof claim 31 wherein said spout includes a shut-off opening formedtherein, and wherein said spacer is generally radially aligned with saidshut-off opening.
 33. The system of claim 21 further comprising a fuelreservoir and a hose fluidly coupled to said nozzle and said fuelreservoir, and a pump configured to pump fuel from said fuel reservoir,through said hose, to said nozzle and through said fuel shaper.
 34. Asystem comprising: a flow shaper configured to be positioned in a spoutsuch that fuel flowing through said spout passes through said flowshaper and exits in a fuel stream, wherein said flow shaper includes anouter wall and a plurality of cavities formed therein, each cavityhaving a L/D ratio of at least about 5:1.
 35. A method for dispensingfuel comprising: providing an nozzle system having a spout with a flowshaper positioned therein; and causing fuel to flow through said nozzlesystem, said spout and said flow shaper such that fuel flowing throughsaid spout passes through said flow shaper and exits in a fuel streamsuch that that at least a majority of the volume of said exiting fuelstream is fully developed or nearly fully developed flow.